延伸一般檔案解譯器管線元件

下列範例說明如何建立自訂解譯器，以剖析使用 UTF-7 編碼的一般檔案文件。 若要處理 UTF-7 檔，元件會繼承自 FFDasmComp 類別，然後覆寫其 GetDataReader 方法。

using System;  
using System.Text;  
using System.IO;  
using Microsoft.BizTalk.Message.Interop;  
using Microsoft.BizTalk.Component.Interop;  
using Microsoft.BizTalk.ParsingEngine;  
using Microsoft.BizTalk.Component;  
using System.Runtime.InteropServices;  
  
namespace Microsoft.BizTalk.Test  
{  
   /// <summary>  
   /// Implements FF disassembler which always uses UTF-7 encoding.  
   /// </summary>  
   [ComponentCategory(CategoryTypes.CATID_PipelineComponent)]  
   [ComponentCategory(CategoryTypes.CATID_DisassemblingParser)]  
   [ComponentCategory(CategoryTypes.CATID_Streamer)]  
   [Guid("A6E5F54F-7902-4e1a-84D8-5C7584F0ECF2")]  
   public class Utf7FFDasm :   
      FFDasmComp,  
      IBaseComponent  
   {  
      /// <summary>  
      /// Initializes a Utf7FFAsmDasm instance.  
      /// </summary>  
      public Utf7FFDasm()  
      {  
      }  
  
      /// <summary>  
      /// Name property  
      /// </summary>  
      public new string Name   
      {  
         get   
         {  
            return "UTF-7 FlatFile Disassembler";  
         }  
      }  
  
      /// <summary>  
      /// Version property  
      /// </summary>  
      public new string Version   
      {  
         get   
         {  
            return "1.0";  
         }  
      }  
  
      /// <summary>  
      /// Description property  
      /// </summary>  
      public new string Description   
      {  
         get   
         {  
            return "UTF-7 FlatFile Disassembler";  
         }  
      }  
  
      /// <summary>  
      /// Gets a data reader instance  
      /// </summary>  
      /// <param name="dataStream">Data stream</param>  
      /// <param name="dataEncoding">Data encoding</param>  
      /// <param name="detectEncodingFromByteOrderMarks">Detect encoding from a byte order mark</param>  
      /// <returns>IDataReader instance</returns>  
      protected override IDataReader GetDataReader(Stream dataStream, Encoding dataEncoding, bool detectEncodingFromByteOrderMarks)  
      {  
         // Delegate call to the base implementation passing fixed UTF-7 encoding  
            return base.GetDataReader(dataStream, Encoding.UTF7, false);  
      }  
   }  
}  

範例

下列範例說明如何建立自訂解譯器，以進行一般檔案交換的交易處理。 不同於標準的「一般檔案解譯器」，在完全處理過整個輸入交換之前，該解譯器不會產生任何解譯的文件。 此元件實作繼承自 FFDasmComp 類別，並覆寫 GetNext 方法。 在第一次呼叫GetNext方法時，它會處理交換中的所有訊息、將它們儲存在ArrayList中，並從ArrayList傳回第一個訊息。 在後續呼叫時，它會從 ArrayList傳回下一則訊息。

注意

以下程式碼範例中，GetNext() 方法的實作應該不適合處理大型文件，因為此實作會傳回記憶體中的整個交換。 對於大型文件使用這項技巧便可能會耗盡記憶體資源，而且會造成效能降低或行為不穩定。

using System;  
using System.Collections;  
using System.Runtime.InteropServices;  
using Microsoft.BizTalk.Message.Interop;  
using Microsoft.BizTalk.Component.Interop;  
using Microsoft.BizTalk.Component;  
  
namespace Microsoft.BizTalk.Component  
{  
   /// <summary>  
   /// Summary description for Class1.  
   /// </summary>  
   [ComponentCategory(CategoryTypes.CATID_PipelineComponent)]  
   [ComponentCategory(CategoryTypes.CATID_DisassemblingParser)]  
   [Guid("EB4714A8-FD97-43de-84E2-E011648F349B")]  
   public class TransactionalFFDasm :   
      FFDasmComp,  
      IBaseComponent,  
      IDisassemblerComponent  
   {  
      public TransactionalFFDasm()  
      {  
      }  
  
      #region IBaseComponent Members  
  
      public new string Description  
      {  
         get  
         {  
            return "Transactional Flat File Disassembler";  
         }  
      }  
  
      public new string Name  
      {  
         get  
         {  
            return "Transactional Flat File Disassembler";  
         }  
      }  
  
      public new string Version  
      {  
         get  
         {  
            return "1.0";  
         }  
      }  
  
      #endregion  
  
      #region IDisassemblerComponent Members  
  
      public new void Disassemble(IPipelineContext pContext, IBaseMessage pInMsg)  
      {  
         base.Disassemble(pContext, pInMsg);  
      }  
  
      public new IBaseMessage GetNext(IPipelineContext pContext)  
      {  
         // Check if don't need to stop collecting messages  
         if (currentMessage == 0)  
         {  
            messageInterchange = new ArrayList();  
            currentMessage = 0;  
  
            // Collect messages from the standard disassembler  
            IBaseMessage disassembledMessage = null;  
            while ((disassembledMessage = base.GetNext(pContext)) != null)  
            {  
               byte[] buffer = new byte[4096];  
               int count = 0;  
  
               // Create a new memory stream to contain the disassembled message.  
               MemoryStream messageStream = new MemoryStream();  
  
               // Get a stream pointer to the disassembled stream.  
               Stream disassembledStream = disassembledMessage.BodyPart.GetOriginalDataStream();  
  
               // Write the disassembled message to the memory stream  
               while (0 != (count == disassembledStream.Read(buffer, 0, 4096)))  
               {  
                  messageStream.Write(buffer, 0, count);  
               } // end-while  
  
               // Rewind the stream to the beginning  
               messageStream.Seek(0, SeekOrigin.Begin);  
  
               // Replace the stream on the disassembled message with the memory stream.  
               disassembledMessage.BodyPart.data = messageStream;  
  
               // Add this message to the ArrayList of messages.  
               messageInterchange.Add(disassembledMessage);  
            } // end-while  
  
            // Check if no messages were collected, just return nothing  
            if (0 == messageInterchange.Count)  
               return null;  
         } // end-if  
  
         // Check if all collected messages are returned  
         if (currentMessage == messageInterchange.Count)  
            return null;  
  
         // Return the current collected message  
         return (IBaseMessage)messageInterchange[currentMessage++];  
      } // end-method GetNext()  
  
      #endregion  
  
      private ArrayList messageInterchange = null;  
      private int currentMessage = 0;  
   }  
}  
  

另請參閱

開發解譯管線元件